review comments

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -301,7 +301,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
             ccx.tcx.disabled_nightly_feature(
                 &mut err,
                 body.source.def_id().as_local().map(|local| ccx.tcx.local_def_id_to_hir_id(local)),
-                vec![(String::new(), feature)].into_iter(),
+                [(String::new(), feature)],
             );
         }
 

compiler/rustc_hir_analysis/src/astconv/generics.rs

@@ -44,7 +44,7 @@ fn generic_arg_mismatch_err(
             tcx.disabled_nightly_feature(
                 &mut err,
                 param.def_id.as_local().map(|local| tcx.local_def_id_to_hir_id(local)),
-                vec![(String::new(), sym::generic_arg_infer)].into_iter(),
+                [(String::new(), sym::generic_arg_infer)],
             );
         }
     }

compiler/rustc_hir_analysis/src/check/mod.rs

@@ -291,8 +291,9 @@ fn default_body_is_unstable(
         reason: reason_str,
     });
 
-    let inject_span =
-        item_did.as_local().and_then(|id| tcx.crate_inject_span(tcx.local_def_id_to_hir_id(id)));
+    let inject_span = item_did
+        .as_local()
+        .and_then(|id| tcx.crate_level_attribute_injection_span(tcx.local_def_id_to_hir_id(id)));
     rustc_session::parse::add_feature_diagnostics_for_issue(
         &mut err,
         &tcx.sess,

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1002,11 +1002,10 @@ fn check_param_wf(tcx: TyCtxt<'_>, param: &hir::GenericParam<'_>) -> Result<(),
                     tcx.disabled_nightly_feature(
                         &mut diag,
                         Some(param.hir_id),
-                        vec![(
+                        [(
                             " more complex and user defined types".to_string(),
                             sym::adt_const_params,
-                        )]
-                        .into_iter(),
+                        )],
                     );
                 }
 

compiler/rustc_middle/src/ty/context.rs

@@ -2175,7 +2175,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Find the crate root and the appropriate span where `use` and outer attributes can be
     /// inserted at.
-    pub fn crate_inject_span(self, hir_id: HirId) -> Option<Span> {
+    pub fn crate_level_attribute_injection_span(self, hir_id: HirId) -> Option<Span> {
         for (_hir_id, node) in self.hir().parent_iter(hir_id) {
             if let hir::Node::Crate(m) = node {
                 return Some(m.spans.inject_use_span.shrink_to_lo());
@@ -2188,14 +2188,15 @@ impl<'tcx> TyCtxt<'tcx> {
         self,
         diag: &mut Diag<'_, E>,
         hir_id: Option<HirId>,
-        features: impl Iterator<Item = (String, Symbol)>,
+        features: impl IntoIterator<Item = (String, Symbol)>,
     ) {
         if !self.sess.is_nightly_build() {
             return;
         }
 
-        let span = hir_id.and_then(|id| self.crate_inject_span(id));
+        let span = hir_id.and_then(|id| self.crate_level_attribute_injection_span(id));
         for (desc, feature) in features {
+            // FIXME: make this string translatable
             let msg =
                 format!("add `#![feature({feature})]` to the crate attributes to enable{desc}");
             if let Some(span) = span {

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -3474,7 +3474,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 tcx.disabled_nightly_feature(
                     err,
                     Some(tcx.local_def_id_to_hir_id(body_id)),
-                    vec![(String::new(), sym::trivial_bounds)].into_iter(),
+                    [(String::new(), sym::trivial_bounds)],
                 );
             }
             ObligationCauseCode::OpaqueReturnType(expr_info) => {